1. Field of the Invention
The present invention relates generally to a rotary damper which progressively or gradually reduces rotational torque in a rotating component of various devices. More specifically, the invention relates to a rotary damper which is easy to manufacture.
2. Description of the Background Art
A conventionally proposed rotary damper employing a coil spring has been disclosed in Japanese Utility Model First (unexamined) Publications (Jikkai) Showa 62-81739 and 62-124343. In such prior proposed construction, a viscous fluid is filled in a cylinder for preventing abrupt variation of the rotating torque with viscous resistance of the fluid. To maintain the viscous fluid, the cylinder has to be formed with substantially high accuracy for establishing a liquid tight seal. The requirement for high accuracy necessarily requires high production cost.